Process for cracking hydrocarbon oils to produce light oils



G. EGLOFF ET AL OriginalFFiled June April 23, 1929.

PROCESS FOR CRACKING HYDROCARBON oILs To PRODUCE LIGHT oILs PatentedApr. 23, 1929.

UNITED STATES y 1,710,153 PATENT oFFicn GUSTV EGLOFF `AND HAERY'I.BENNER, OF CHIGAGO, ILLINOIS, ASSIGNORS TO UNI- VERSAL OIL PRODUCTSCOMPANY, QF CHICAGO, ILLINOIS, A CGRPRATION OF scura nuora.,

EDRGGESS FOR GRGKING EYDROCALRBQN OILS r`.UO PRODUCE LIGHT OILS.

Application filed .Tune 2S, 1920, Serial No. 322,475. Renewed Februaryl2, 1927.

@ur invention relates to a process and apparatus for cracking heavyhydrocarbon oils by ineans oi? heat and pressure in a double highpressure still, and means of internally heating same for the production'of light oils characteristically gasoline, or the like. y y

lts salient objects are to provide a pressure rlistillation process forcracking heavy hydrocarbon oils to produce light oils therefrom; toprovide a process which may be operated continuously for the pressuredistillation oit heavy hydrocarbon oils to produce light oils therefromby lmeans of a combustion chamber set Within the body of ythe doublehigh pressure still; to provide a process for the pressure distillationof heavy hydrocarbon oils to produce light oils thereilroin by nieansota double high pressure still superheating the hydrocarbon vaporsgenerated by one of said double high pressure stills; to provide apressure distillation process 'for the heavy hydrocarbon voils toproduce light oils, such as gasoline or the like, :trom said heavyhydrocarbon oils by means of charging the lower of .the double highpressure still and spraying untreated oil continuously over said oilWhile on pressure distillation; to provide a process tor the pressuredistillation of heavy hydrocarbon oils to produce light oils therefromby means of a double high ypressure still in which both stills of. saiddouble high pressure still are charged with said hydrocarbon oil to betreated, and continuously charging untreated oil to the system duringpressure distillation.

The following is a description of an apparatus as shown in the drawing.

The numeral l represents a gas burner set in corrugated tube 2, which isWithin high pressure still 6. 2a is a connection*` between corrugatedtube 2 and corrugated tube 8 set in pressure still 5, to which tube 3stack 4 is attached. A vapor line connects pressure still 5 throughvalve 8 and pipe 9 to dephlegmator 10 having baille plates ll settherein and provided with an inverted dish l2, and dephlegmated oil trap13. The numeral 13a, designates fa dephlegrnated` oil or reflex returnpipe attached to the lower part of still 6. The numeral 14 desi nates avapor conduit connected with dep legmator 10 in which conduit is placedvalve 15. The pipe extension 15aA leads to condenser.l coil 16, setWithin Water .condenser box l?. The condensed pressure distillate oil`passing through pipe 18. with iincoiidcnsable gas from condenser coil16 passes to receiver 19. Pipe 2O is attached to receiver 19 withpressure distillate controlvalve`2l, having pipe 2l.a connectcd withstorage tank `iltor pressure distillate oil. Pipe 23 is uncondensablegas line controlled by valve 22,1 Pipe 221" is connected touiicondensable gas tank.. The numeral 24 represents pressure gage, and24 the gauge' glass upon receiver 19. A raw oil puin) 25, pumps raw oilvia valve 26 and discharges through control valve 27, through preheatercoil 28. A control valve 27 is used for passing raw oil throughpreheater coil 28 set in the path of combustion gases in liuc 2a. Thepreheated raw oil from coil 28 passes through pipe 29 set in still t,having pertorations 30, through which the oil` sprays into said still dThe numeral 6a represents nozzles which connect still t with still 5,being projected above the bottoni of still 5. Insulating `iiiatei'ial 5surrounds stills 5 and 6. 3l is draw od pipe for residuum from still 6,controlled by valve 32, attached to pipe connection 33 with storage tankfor said residuumoil.

One typical. method of operation of this process and apparatus whencracking a very refractory oil, such as steam still kerosene bottoms,Pine Island gas oil and the like, is to charge still 6 with one of saidoils by means of raw oil pump 25, through coil 28 and pipe 29, or still6 may be charged by vvay of residuum line` 31, connected with valve 32and pipe connections 33 by means ot' pump not shown. The ressuredistillate control valve 21 and uncon ensable gas valve 23 are closed.Valves 8 and 15 are opened. Burner l is ignited, the products ofcombustion passing corrugated tube 2., connections 2* attached tocorrugated tube 3, set in still 5, passing out of stack 4l.. Thehydrocarbon vapors generated in the system produce a generated pressureupon the entire system which is predetermined dependent upon thev typeof oil used. After the desired self-impressed pressure has been createdin the system the operation may be continued under such ressure bysuitably controlling the thrott 'e valves 21 and 22 on the receiver 19tcel The hydrocarbon vapors generated in vstill 6 w passing through.pipes 6, connected to still are superheated by the products of comfbustion, passing through corrugated tube 3. The hydrocarbon vaporsfromstill 5, passing through pipe 7, valve 8 and pipe 9, attached todephlegmator 11 are fractionated, so that only the lighter vapors ypassout' throughconduit 14, valves 15 and pipe 15a to be condensed incondenser coil 16, running into receiver 19 when the system is 011pressure distillation.' The dephlegmated liquid con" densed indephlegmator 10 drops back in said dephlegmator to the. trap 13, passingdown throu h pipe connections 13'? to the lower part o still 6.- Itisimportant to'note in this j process and apparatus t at we do awayentirely with furnace construction of brick work or like material.

pressure distillation VWe also do away with high furnace boxconstruction which necessitates all construction work on pressuredistillation processesbeing l built 8 or l() feet higher than ourprocess from` percent o and apparatus. We have Ifound that this cutsdown the construction costs markedlyand is an important feature of ourprocess and apparatus.` Our process and apparatus alsok economizes upon'fuel consumption, as the products of combustion, pass through theinternal part of the still so that we do away with radiating heat' fromfurnace walls and reduce heat loss to a minimum. Our stills are heavilyinsulated with magnesia brick or kieselguhr. It is to be iioted that 1the productsof combustion within the lower still pass on after giving uppart of their heat content to the liquid in said lower still and Ysuperheat the vapors in the upperstill, which then pass out through thedephle ator. We also have found that by preheating the raw oil fed intothe system by means of waste products of combustion, that the'ca` pacityof the stills is increased.

A typical operating run was to distil a Pine Island gas oil of 31.0Baume gravity at apressure of 125 pounds, producing therea pressuredistillate. oil

` of 51.0 Baum gravity containing therein 55 ercent of a 57-58 Baumgravity gasoline.

his yielded 33 percent' of 57-58 Baum` gravity gsoline on the basis ofoil used.

The a ve is the preferred method of operation of this process andapparatus. However, when using easily crackable oils, Such as fuel oils,heavy residuums,` heavy crude oils we may charge both stills with one ofsaid oils and spray in raw chargingoil into the upper still instead ofthe lower.

We do not limit ourselves yto any particular amount of still charge,because this is determined by the type oilv which is to be .cracked inour process. Nor'does the e dephlegmator u on the system, as shown 1ndrawing, act a vantageously on all hydrocarbon o1ls.' We have found that`the char-tclosed conduit located within said still, inv

passing the vapors generated in said lower still to the upper stillwherein they are superheated by passing thecombustion gases through aclosed conduit located in said upperistill, in continuously introducinga spray of preheated oil into said bulk supply of oil, in dephleginatingthe vapors passing over from saidupper still, in returning the refluxkcondensate resulting from such dephle ation to said bulk supply of oil,in

'continuously withdrawing heavy residuuin from said bulk supply of oilandin maintaining a superatmospheric vapor pressure on the oilundergoing conversion.

2. A process of treating hydrocarbon oil, consisting in charging thelower of a pair of interconnected stills with a bulk supply of oil, inheating the bulk supply of oil in said lower still by passin the heatinggases through a closed con uit disposed therein,

in passing the vapors generated from said Y bulk1 supply of oil to theup er of said pairl of stills, and in there super eating they vapors byassing the combustion gases through a c osed conduit disposed therein,in continuously introducing raw oil to said bulk supply of oil through aspray, in dephleg- -mating the vapors issuing from said upper still, andin condensing and collecting they resulting distillate.

3. A comprising placing the oil to be cracked under ressure, initiallypassing the oil through an e ongated conduit of restricted cross sectionabout which gases of combustion pass to.

impart heat to the oil, subsequently delivering theoil in the formy ofaspray to an enr larged zone wherein the oil spray iscaused to directlycontact with the exterior surface of a' heating element, through whichcom# bustion gases of a higher temperature .than the combustion gasespassing about said conduit are flowing, in maintaining a pressure on theoilI in such elongatedv conduit and in saidenlargedi'fzone in excess of100 pounds per square inch in removing vapor generated from the oiland'in subjecting such vapors to condensation and collection.

rocess for cracking petroleum oil 4. A process for cracking petroleumoil I comprising' placingI the oil to be cracked'.

under pressure, initially passing 'thel oil through an elongated conduitof restricted from the toil as the result of said heat treat- 10 mentand in passingr such vapors in heat interchange relatlon with combustiongases Whlch have been previously passed about said conduit, inthereafter subjecting the va pors to dephlegmation and condensation.

GUSTAV EGLOFF. HARRY P. BENNER. v

